Hi Rockhopper,
Regret I don't have time to scan in some slides to show where the routes go on the middle tier of Arrow, but the original Arrow Buttress route is fine climbing at E grade (9-11) following a line on the left side and going past a noticeable white arrowhead marking.
The right hand side has a prominent flat face, and Sagittarius (F2-14) goes up the middle to left side of that, whereas what climbers used to call the middle section of Fraser's (though it is doubtful as was never described in the MCSA Journal) starts at an undercut crack/edge with a pull-up and continues up the large flat face (grade F1-13)
Good luck finding the climbs as they are fun and you should enjoy them.
Mike Scott